Semiconductor capacitor

ABSTRACT

A one time programmable memory cell having a gate, a gate dielectric layer, a source region, a drain region, a capacitor dielectric layer and a conductive plug is provided herein. The gate dielectric layer is disposed on a substrate. The gate is disposed on the gate dielectric layer. The source region and the drain region are disposed in the substrate at the sides of the gate, respectively. The capacitor dielectric layer is disposed on the source region. The capacitor dielectric layer is a resistive protection oxide layer or a self-aligned salicide block layer. The conductive plug is disposed on the capacitor dielectric layer. The conductive plug is served as a first electrode of a capacitor and the source region is served as a second electrode of the capacitor. The one time programmable memory (OTP) cell is programmed by making the capacitor dielectric layer breakdown.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of U.S.A. provisionalapplication Ser. No. 60/807,615, filed on Jul. 18, 2006, all disclosuresare incorporated therewith.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a semiconductor device, inparticular, to a semiconductor capacitor, a one time programmable memorycell and a fabricating method and an operating method thereof.

2. Description of Related Art

With the advantage of retaining the stored data even after power to thedevice is cut-off, the non-volatile memory device has become a kind ofmemory device wildly employed in personal computers and electronicdevices.

Generally, non-volatile memories is classified as erasable programmableread only memory (EPROM), electrically erasable programmable read onlymemory (EEPROM), mask read only memory and one time programmable readonly memory (OTPROM) etc.

With respect to EPROM and EEPROM, due to their recordable and erasablecapabilities, EPROM and EEPROM are preferable choices in practice.However, the manufacturing process of EPROM and EEPROM is relativelycomplex and costly.

With respect to mask ROM, though the manufacturing process is relativelysimple and the cost is relatively low, masks are required to define datato be recorded. Thus, there are many limitations during usage.

With respect to one time programmable ROM, because data is recordedafter the memories have been left the factory, that is, data is recordedby users according to configuration situations of the memories, they aremore convenient than mask ROM in practice.

When semiconductor technology enters deep sub-micron manufacturingprocess, the size of device is gradually decreased, which meansdecreased memory cell size with respect to memory device. On the otherhand, as data which information electronic products (such as computer,mobile phone, digital camera and personal digital assistant (PDA)) haveto handle and store are increased, the memory capacity required in theseinformation electronic products becomes larger and larger. In the caseof decreased device size and increased memory capacity demand, a commongoal in the field is how to fabricate memory devices having decreasedsize, high integration and still keeping good qualities.

SUMMARY OF THE INVENTION

Therefore, the present invention provides a semiconductor capacitorwhich utilizes a resistive protection oxide layer or a self-alignedsilicide block layer as a capacitor dielectric layer. No additionalmanufacturing process is required, so the manufacturing process of thesemiconductor device is simple, and the integration of thissemiconductor device is increased.

The present invention provides a one time programmable memory cell whichutilizes a resistive protection oxide layer or a self-aligned silicideblock layer as a capacitor dielectric layer and utilizes a source of atransistor and a conductive plug as electrodes of a capacitor. The sizeof this device is decreased and the integration of this semiconductordevice is increased.

The present invention provides a fabricating method of a one timeprogrammable memory cell. This method is compatible with commoncomplementary metal oxide-semiconductor manufacturing processes. Noadditional manufacturing process is required.

The present invention provides an operating method of a one timeprogrammable memory cell. The method includes programming memory cellsby making a capacitor dielectric layer breakdown. The memory cells arerecorded one time and data stored in the memory cells are non-volatile.

The present invention provides a semiconductor capacitor including acapacitor dielectric layer, a first electrode and a second electrode.The capacitor dielectric layer is a resistive protection oxide layer ora self-aligned silicide block layer. The first and second electrodes aredisposed at the opposing sides of the capacitor dielectric layer.

According to one preferred embodiment of the present invention, thefirst electrode is a conductive plug.

According to one preferred embodiment of the present invention, thesemiconductor capacitor further includes an etch stop layer disposed onthe capacitor dielectric layer. The first electrode extends through theetch stop layer and contacts with the capacitor dielectric layer.

According to one preferred embodiment of the present invention, thesemiconductor capacitor is disposed on a substrate. The second electrodeis a doped region disposed in the substrate. The capacitor dielectriclayer is disposed on the doped region and exposes a portion of the dopedregion. The first electrode is disposed on the capacitor dielectriclayer.

According to one preferred embodiment of the present invention, thesubstrate includes a silicon substrate.

According to one preferred embodiment of the present invention, thesemiconductor capacitor further includes a metal silicide layer and asecond conductive plug. The metal silicide layer is disposed on thedoped region exposed from the capacitor dielectric layer. The secondconductive plug is electrically connected to the metal silicide layer.

According to one preferred embodiment of the present invention, thefirst electrode is formed from one or more first conductive plugs. Theshape of the first conductive plug is square, rectangle, round or othershapes.

According to one preferred embodiment of the present invention, thesubstrate is a silicon on insulator substrate. The doped region isdisposed in a silicon layer of the silicon on insulator substrate.

According to one preferred embodiment of the present invention, thesemiconductor capacitor further includes a metal silicide layer and asecond conductive plug. The metal silicide layer is disposed on thedoped region exposed from the capacitor dielectric layer. The secondconductive plug is electrically connected to the metal silicide layer.

According to one preferred embodiment of the present invention, thefirst electrode is formed from one or more first conductive plugs. Theshape of the first conductive plug is square, rectangle, round or othershapes.

According to one preferred embodiment of the present invention, thesemiconductor capacitor is disposed on an isolation structure of thesubstrate. The second electrode is a doped polysilicon layer disposed onthe substrate. The capacitor dielectric layer is disposed on the dopedpolysilicon layer and exposes a portion of the doped polysilicon layer.The first electrode is disposed on the capacitor dielectric layer.

According to one preferred embodiment of the present invention, thesemiconductor capacitor further includes a metal silicide layer and asecond conductive plug. The metal silicide layer is disposed on thedoped region exposed from the capacitor dielectric layer. The secondconductive plug is electrically connected to the metal silicide layer.

According to one preferred embodiment of the present invention, thefirst electrode is formed from one or more first conductive plugs. Theshape of the first conductive plug is square, rectangle, round or othershapes.

According to one preferred embodiment of the present invention, thesemiconductor capacitor is disposed on an insulating substrate. Thesecond electrode is a doped semiconductor layer disposed on theinsulating substrate. The capacitor dielectric layer is disposed on thedoped semiconductor layer and exposes a portion of a doped semiconductorlayer. The first electrode is disposed on the capacitor dielectriclayer.

According to one preferred embodiment of the present invention, thesemiconductor capacitor further includes a metal silicide layer and asecond conductive plug. The metal silicide layer is disposed on thedoped semiconductor layer exposed from the capacitor dielectric layer.The second conductive plug is electrically connected to the metalsilicide layer.

According to one preferred embodiment of the present invention, thefirst electrode is formed from one or more first conductive plugs. Theshape of the first conductive plug is square, rectangle, round or othershapes.

According to one preferred embodiment of the present invention, theinsulating substrate is a glass substrate.

In the semiconductor capacitor of the present invention, a resistiveprotection oxide layer or a self-aligned silicide block layer is servedas a capacitor dielectric layer, and a conductive plug (first electrode)and a doped region or a doped semiconductor layer (second electrode) areserved as electrodes of the capacitor. Wherein, the doped region is asource/drain region of a transistor or is fabricated together with asource/drain region of the transistor in a same manufacturing process.The doped semiconductor layer is fabricated together with a gate of thetransistor in a same manufacturing process. The conductive plug isfabricated together with plugs connected to the gate, source/drainregion of the transistor in a same manufacturing process. Therefore, acapacitor is fabricated without varying the manufacturing process ofcommon complementary metal oxide-semiconductor, the integration ofsemiconductor devices is elevated and the cost of manufacture isreduced.

The present invention provides a one time programmable memory cellincluding a gate, a gate dielectric layer, a source region, a drainregion, a capacitor dielectric layer, and a conductive plug. The gatedielectric layer is disposed on a substrate. The gate is disposed on thegate dielectric layer. The source and drain regions are disposed in thesubstrate at the sides of the gate, respectively. The capacitordielectric layer is disposed on the source region, and the capacitordielectric layer is a resistive protection oxide layer or a self-alignedsilicide block layer. The conductive plug is disposed on the capacitordielectric layer, wherein the conductive plug is served as a firstelectrode of a capacitor, and the source region is served as a secondelectrode of the capacitor.

In the one time programmable memory cell of the present invention, aresistive protection oxide layer or a self-aligned silicide block layeris served as a capacitor dielectric layer, and a conductive plug and asource region are served as electrodes of a capacitor. Therefore, thecapacitor is fabricated without varying the manufacturing process ofcommon complementary metal oxide-semiconductor. The capacitor isdirectly disposed on the source region, so the integration ofsemiconductor devices is elevated and the cost of manufacture isreduced.

The present invention provides an operating method of a one timeprogrammable memory cell, the memory cell includes a substrate of firstconductive type, a gate dielectric layer and a gate disposed on thesubstrate of first conductive type, a source region and a drain regionof second conductive type disposed in the substrate of first conductivetype at the sides of the gate, a capacitor dielectric layer disposed onthe source region of second conductive type and a conductive plugdisposed on the capacitor dielectric layer, wherein the capacitordielectric layer is a resistive protection oxide layer or a self-alignedsilicide block layer. This method includes programming the memory cellby making the capacitor dielectric layer breakdown.

According to one preferred embodiment of the present invention, thefirst conductive type is P-type, and the second conductive type isN-type. The process of programming the memory cell includes followingsteps. A first voltage is applied on the conductive plug, a secondvoltage is applied on the substrate of first conductive type, a thirdvoltage is applied on the drain region of second conductive type, and afourth voltage is applied on the gate. The first, second and thirdvoltages are set to make the capacitor dielectric layer breakdown. Thefourth voltage is set to open a channel under the gate.

According to one preferred embodiment of the present invention, thefirst voltage is about 4 to 6 Volts, the second voltage is about 0 Volt,the third voltage is about 0 Volt, the fourth voltage is about 1 to 2Volts.

According to one preferred embodiment of the present invention, thesubstrate of first conductive type includes a well of second conductivetype and a well of first conductive type disposed on the well of secondconductive type. The first conductive type is P type, and the secondconductive type is N type. The process of programming the memory cellincludes following steps. The substrate of first conductive type and thewell of second conductive type are grounding, a fifth voltage is appliedon the conductive plug, a sixth voltage is applied on the gate, aseventh voltage is applying on the drain region of second conductivetype and a eighth voltage is applied on the well of first conductivetype. The fifth, seventh and eighth voltages are set to make thecapacitor dielectric layer breakdown. The sixth voltage is set to open achannel under the gate.

According to one preferred embodiment of the present invention, thefifth voltage is about 3.3 Volts, the sixth voltage is about 0 Volt, theseventh voltage is about −3.3 Volts, and the eighth voltage is about−3.3 Volts.

According to one preferred embodiment of the present invention, thefirst conductive type is N type, and the second conductive type is Ptype. The process of programming the memory cell includes followingsteps. A ninth voltage is applied on the conductive plug, a tenthvoltage is applied on the substrate of first conductive type and aeleventh voltage is applied on the drain region of second conductivetype, a twelfth voltage is applied on the gate. The ninth, tenth andeleventh voltage are set to make the capacitor dielectric layerbreakdown, the twelfth voltage is set to open a channel under the gate.

According to one preferred embodiment of the present invention, theninth voltage is about −3.3 Volts, the tenth voltage is about 3.3 Volts,the eleventh voltage is about 3.3 Volts, and the twelfth voltage isabout 0 Volt.

According to one preferred embodiment of the present invention, thefirst conductive type is N type, and the second conductive type is Ptype. The process of programming the memory cell includes followingsteps. A thirteenth voltage is applied on the conductive plug, afourteenth voltage is applied on the substrate of first conductive typeand a fifteenth voltage is applied on the gate, a sixteenth voltage isapplied on the drain region of second conductive type. The thirteenthvoltage, the fourteenth voltage and sixteenth voltage are set to makethe capacitor dielectric layer breakdown.

According to one preferred embodiment of the present invention, thethirteenth voltage is about 0 Volt, the fourteenth voltage is about 4 to6 Volts, the fifteenth voltage is about 3.3 Volts, and the sixteenthvoltage is about 4 to 6 Volts.

According to one preferred embodiment of the present invention, duringprogramming, a dielectric layer of a capacitor is damaged (breakdown) bycontrolling voltages applied on a gate, a drain, a source and asubstrate of a transistor. Digital information “0” or “1” is recorded bydetecting whether the dielectric layer of the capacitor is damaged ornot. The contact area of conductive plug with the capacitor dielectriclayer is relatively small, which can result in increased current destinywhere the conductive plug contacts with the capacitor dielectric layerwhen a one time programmable memory cell of the present invention isprogrammed. This can readily make the capacitor dielectric layerbreakdown and the operating voltages are reduced.

The present invention provides a fabricating method of a one timeprogrammable memory cell. At first, a substrate provided with atransistor thereon is provided. The transistor includes a gate, a firstsource/drain region and a second source/drain region. Next, a dielectriclayer is formed on the first source/drain region. The dielectric layeris a resistive protection oxide layer or a self-aligned silicide blocklayer. Subsequently, a metal silicide layer is formed on the gate andthe second source/drain region. Then, a first conductive plug is formedon the dielectric layer. The first conductive plug, the dielectric layerand the first source/drain region form a capacitor.

According to one preferred embodiment of the present invention, the stepof forming the dielectric layer on the first source/drain regionincludes following sub-steps. At first, the dielectric layer is formedon a substrate and a mask layer covering the first source/drain regionis formed on the substrate. Subsequently, the mask layer is served as amask and the portion of the dielectric layer uncovered by the mask isremoved. Then, the mask layer is removed.

According to one preferred embodiment of the present invention, an etchstop layer and an interlayer insulating layer are formed on thesubstrate before the step of forming the first conductive plug on thedielectric layer.

According to one preferred embodiment of the present invention, thematerial of the etch stop layer includes silicon nitride (SiN) orsilicon oxynitride (SiON).

According to one preferred embodiment of the present invention, the stepof forming the first conductive plug on the dielectric layer furtherincludes forming a second conductive plug electrically connected to thesecond source/drain region.

According to one preferred embodiment of the present invention, thematerial of the dielectric layer includes silicon oxide.

According to one preferred embodiment of the present invention, theprocess of forming the metal silicide layer on the gate and the secondsource/drain region includes self-aligning metal silicides process.

In the fabricating method of a one time programmable memory cell of thepresent invention, a capacitor is directly formed from a firstconductive plug, a resistive protection oxide layer or a self-alignedsilicide block layer and a first source/drain region. The capacitor isfabricated without varying common complementary metaloxide-semiconductor manufacturing process, and the capacitor is directlydisposed on the first source/drain region. No additional space isrequired and the integration of semiconductor devices is elevated.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will bedescribed and become more apparent from the detailed description ofexemplary embodiments when read in conjunction with accompanyingdrawings.

FIG. 1A is a schematic top view illustrating a semiconductor capacitoraccording to a preferred embodiment of the present invention.

FIGS. 1B and 1C are top views illustrating a semiconductor capacitoraccording to another preferred embodiment of the present invention,respectively.

FIG. 2A is a cross-sectional view taken along line A-A′ in FIG. 1A.

FIGS. 2B to 2D are cross-sectional views illustrating other preferredembodiments of the semiconductor capacitor according to the presentinvention, respectively.

FIG. 3A is a schematic view of a one time programmable memory cellaccording to a preferred embodiment of the present invention.

FIGS. 3B and 3C are schematic circuit diagrams of the one timeprogrammable memory cell according to the present invention.

FIGS. 4A to 4B are schematic views illustrating programming operation ofan N type memory cell, respectively.

FIGS. 5A to 5B are schematic views illustrating programming operation ofa P type memory cell, respectively.

FIGS. 6A to 6E are cross-sectional views illustrating a manufacturingprocess of a one programmable memory cell according to one preferredembodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

The present invention provides a semiconductor capacitor, a one timeprogrammable memory cell having the semiconductor capacitor and afabricating method and an operating method thereof.

At first, a semiconductor capacitor according to the present inventionwill be described.

FIG. 1A is a schematic top view illustrating a semiconductor capacitoraccording to a preferred embodiment of the present invention. FIG. 2A isa cross-sectional view taken along line A-A′ in FIG. 1A. FIGS. 1B and 1Care top views illustrating a semiconductor capacitor according toanother preferred embodiment of the present invention, respectively. Themembers in FIGS. 1B and 1C that are same with those in FIG. 1A will bedesignated by same reference numbers, respectively and theirillustrations will be omitted.

Please refer to FIGS. 1A and 2A, a semiconductor capacitor according tothe present invention is disposed on a substrate 100, for example. Thesubstrate 100 is provided with an isolation structure 102 to define anactive area. For example, the isolation structure 102 is a shallowtrench isolation structure or a field oxide layer. The semiconductorcapacitor is formed from a conductive plug 112 (first electrode), acapacitor dielectric layer 106 and a doped region 104 (secondelectrode). The conductive plug 112 (first electrode) and the dopedregion 104 (second electrode) are served as electrodes of thesemiconductor capacitor.

For example, the substrate 100 is a silicon substrate. The capacitordielectric layer 106 is, for example, a resistive protection oxide layeror a self-aligned silicide block layer commonly used in semiconductormanufacturing process. The material of the capacitor dielectric layer106 is silicon oxide, silicon nitride or other dielectric material (e.g.high-k material).

The conductive plug 112 (first electrode) and the doped region 104(second electrode) are disposed at the opposing sides of the capacitordielectric layer 106. The doped region 104 (second electrode) isdisposed in the substrate 100, for example. The capacitor dielectriclayer 106 is, for example, disposed on the doped region 104 (secondelectrode), and can expose a portion of the doped region 104 (secondelectrode). The conductive plug 112 (first electrode) is disposed on thecapacitor dielectric layer 106. As shown in FIG. 1A, the capacitordielectric layer 106 only covers a portion of the doped region 104(second electrode).

For example, a metal silicide layer 108 is disposed on the doped region104 (second electrode) exposed from the capacitor dielectric layer 106.The material of the metal silicide layer 108 includes metal silicide ofrefractory metal, such as one silicide of nickel, cobalt, titanium,copper, molybdenum, tantalum, tungsten, erbium, zirconium, platinum andsilicide of alloys thereof.

For example, an etch stop layer 110 is disposed on the capacitordielectric layer 106 and the doped region 104 (second electrode). Thematerial of the etch stop layer 110 is, for example, silicon nitride orsilicon oxynitride. The conductive plug 112 (first electrode) extendsthrough the etch stop layer 110 and contacts with the capacitordielectric layer 106. The etch stop layer 110 plays a very importantrole in the manufacturing process of the conductive plug 112. Theprimary reason is that the etch stop layer 110 can give more stablyetching process of forming plugs, it can make etching of the plugs tostop at the etch stop layer 110 by utilizing different etchingselectivity of different materials. Finally, the etch stop layer 110 isbe etched. In present invention, because a resistive protection oxidelayer or a self-aligned silicide block layer is disposed under the etchstop layer 110, etching will stop at the resistive protection oxidelayer or the self-aligned silicide block layer, the conductive plug 112(first electrode) of the capacitor dielectric layer 106 is readilyformed.

An interlayer insulating layer 116 is further disposed on the etch stoplayer 110. The interlayer insulating layer 116 is, for example,phosphorosilicate glass borophosphorosilicate glass etc. The conductiveplug 112 (first electrode) and the conductive plug 114 which iselectrically connected to the metal silicide layer 108 are disposed inthe interlayer insulating layer 116. The material of the conductive plug112 (first electrode) and the conductive plug 114 includes conductivematerial such as metal material or doped polysilicon.

Seen from the top view of FIG. 1A, the shape of the conductive plug 112(first electrode) is, for example, square. Of course, the shape of theconductive plug 112 (first electrode) can also be rectangle as shown inFIG. 1B, or other suitable shapes such as round or oval. Additionally,the first electrode of the semiconductor capacitor in the presentinvention is not only limited to one. As also shown in FIG. 1C, two ormore conductive plugs 112 a, 112 b (first electrode) is provided.

FIGS. 2B to 2D are cross-sectional views illustrating other preferredembodiments of the semiconductor capacitor according to the presentinvention, respectively. In FIGS. 2B to 2D, members which are same withthose in FIG. 1A are designated by same reference numbers, respectively,and their illustrations will be omitted.

Please refer to FIG. 2B, a semiconductor capacitor is disposed on asilicon on insulator (SOI) substrate 100 a, for example. The silicon oninsulator substrate 100 a is formed from, for example, a substrate layer101 a, an insulating layer 101 b and a silicon layer 101 c.

The doped region 104 (second electrode) is, for example, disposed in thesilicon layer 101 c of the silicon on insulator substrate 100 a. Thecapacitor dielectric layer 106 is, for example, disposed on the siliconlayer 101 c, and exposes a portion of the doped region 104 (secondelectrode). The conductive plug 112 (first electrode) is, for example,disposed on the capacitor dielectric layer 106.

The metal silicide layer 108 is disposed on the doped region 104 (secondelectrode) which is exposed on the capacitor dielectric layer 106, andthe etch stop layer 110 is disposed on the capacitor dielectric layer106 and the doped region 104 (second electrode). The interlayerinsulating layer 116 is disposed on the etch stop layer 110, forexample. The shape of the conductive plug 112 (first electrode) is, forexample, square, rectangle or other suitable shapes such as round oroval. The number of the conductive plug 112 (first electrode) is notonly limited to one, and can also be two or more.

In the semiconductor capacitors shown in FIGS. 2A and 2B, a resistiveprotection oxide layer or a self-aligned silicide block layer is servedas the capacitor dielectric layer 106, and the conductive plug 112 andthe doped region 104 are served as electrodes of a capacitor. The dopedregion 104 is a source/drain region of a transistor or is fabricatedtogether with a source/drain region of a transistor in a samemanufacturing process. The conductive plug 112 is fabricated togetherwith plugs connected to a gate, source/drain region of a transistor in asame manufacturing process. Therefore, a capacitor is fabricated withoutvarying the manufacturing process of common complementary metaloxide-semiconductor. No additional space is required, and theintegration of semiconductor devices is elevated.

Please refer to FIG. 2C, a semiconductor capacitor is, for example,disposed on an insulating substrate 100 b. The insulating substrate 100b is, for example, a glass substrate or a plastic substrate etc.

A doped semiconductor layer 104 a (second electrode) is, for example,disposed on the insulating substrate 100 b. The material of the dopedsemiconductor layer 104 a is, for example, doped silicon or dopedpolysilicon etc. The doped semiconductor layer 104 a and a gate layer ofa transistor are fabricated in a same manufacturing process. That is,while patterning a gate of a MOS transistor, a doped semiconductor layer104 a (second electrode) of a capacitor is defined. Therefore, no otheradditional steps are required, when the capacitor of the presentinvention is fabricated. A capacitor dielectric layer 106 is, forexample, disposed on the doped semiconductor layer 104 a (secondelectrode), and exposes a portion of the doped semiconductor layer 104 a(second electrode). The conductive plug 112 (first electrode) is, forexample, disposed on the capacitor dielectric layer 106.

The metal silicide layer 108 is, for example, disposed on the dopedsemiconductor layer 104 a (second electrode) exposed from the capacitordielectric layer 106 and the etch stop layer 110 is disposed on thecapacitor dielectric layer 106 and the doped semiconductor layer 104 a(second electrode). The interlayer insulating layer 116 is disposed onthe etch stop layer 110, for example. The shape of the conductive plug112 (first electrode) is, for example, square, rectangle or othersuitable shapes such as round or oval. The number of the conductive plug112 (first electrode) is not only limited to one, and can also be two ormore. Additionally, an insulating spacer 118 is, for example, disposedon a sidewall of the doped semiconductor layer 104 a. The material ofthe insulating spacer 118 is, for example, silicon oxide or siliconnitride etc.

Please refer to FIG. 2D, a semiconductor capacitor is, for example,disposed on an isolation structure 102 a of the substrate 100.

A doped semiconductor layer 104 b (second electrode) is, for example,disposed on the isolation structure 102 a. The material of the dopedsemiconductor layer 104 b is, for example, doped silicon or dopedpolysilicon etc. Similarly, the doped semiconductor layer 104 b and agate layer of a transistor are fabricated in a same manufacturingprocess. That is, while patterning a gate of a MOS transistor, the dopedsemiconductor layer 104 b (second electrode) of a capacitor is defined.Therefore, no other additional steps are required, when a capacitor ofthe present invention is fabricated. The capacitor dielectric layer 106is, for example, disposed on the doped semiconductor layer 104 b (secondelectrode), and exposes a portion of the doped semiconductor layer 104 b(second electrode). The conductive plug 112 (first electrode) is, forexample, disposed on the capacitor dielectric layer 106.

The metal silicide layer 108 is, for example, disposed on the dopedsemiconductor layer 104 b (second electrode) exposed from the capacitordielectric layer 106 and the etch stop layer 110 is disposed on thecapacitor dielectric layer 106 and the doped semiconductor layer 104 b(second electrode). The interlayer insulating layer 116 is, for example,disposed on the etch stop layer 110. The shape of the conductive plug112 (first electrode) is, for example, square, rectangle or othersuitable shapes such as round or oval. The number of the conductive plug112 (first electrode) is not only limited to one, and can also be two ormore. Additionally, the insulating spacers 118 are, for example,disposed on sidewalls of the doped semiconductor layer 104 a. Thematerial of the insulating spacers 118 is, for example, silicon oxide orsilicon nitride etc.

In the semiconductor capacitors in FIGS. 2C to 2D, a resistiveprotection oxide layer or a self-aligned silicide block layer is servedas the capacitor dielectric layer 106, and the conductive plug 112 andthe doped semiconductor layer 104 a (104 b) are served as electrodes ofa capacitor. The doped semiconductor layer 104 a (104 b) is fabricatedtogether with a gate of a transistor in a same manufacturing process.The conductive plug 112 is fabricated together with plugs connected to agate, source/drain region of a transistor in a same manufacturingprocess. Therefore, a capacitor is fabricated without varying themanufacturing process of common complementary metal oxide-semiconductor.No additional space is required, and the integration of semiconductordevices is elevated.

Next, a one time programmable memory cell of the present invention willbe described. The one time programmable memory cell of the presentinvention includes the aforementioned semiconductor capacitor.

FIG. 3A is a schematic view of a one time programmable memory cellaccording to a preferred embodiment of the present invention. FIGS. 3Band 3C are schematic circuit diagrams of the one time programmablememory cell according to the present invention.

Please refer to FIG. 3A, the one time programmable memory cell of thepresent invention is disposed on a substrate 200. The one timeprogrammable memory cell includes a gate dielectric layer 202, a gate204, a source region 206, a drain region 208, spacers 210, a capacitordielectric layer 212, a conductive plug 214 and an etch stop layer 216.The one time programmable memory cell of the present invention can be anN type channel memory cell, and can also be a P type channel memorycell.

The gate 204 is, for example, disposed on the substrate 200. Thematerial of the gate 204 includes conductive material, such as metal ordoped polysilicon. The gate dielectric layer 202 is, for example,disposed between the gate 204 and the substrate 200. The martial of thegate dielectric layer 202 includes silicon oxide or high-k materialhaving dielectric constant higher than 4. The gate dielectric layer 202can also be formed from one or more dielectric material layers. Forexample, the gate dielectric layer 202 is formed from a single siliconoxide layer or from a silicon oxide layer and a high-k material layer.

The spacers 210 are, for example, disposed on sidewalls of the gate 204.The material of the spacers 210 is, for example, silicon oxide orsilicon nitride. The source region 206 and the drain region 208 aredisposed in the substrate 200 on the sides of the gate 204,respectively.

The capacitor dielectric layer 212 is, for example, disposed on thesource region 206, and the capacitor dielectric layer 212 is a resistiveprotection oxide layer or a self-aligned silicide block layer. Thematerial of the capacitor dielectric layer 212 is, for example, siliconoxide or silicon nitride.

The conductive plug 214 is, for example, disposed on the capacitordielectric layer 212. The conductive plug 214 is served as a firstelectrode of a capacitor, the source region 206 is served as a secondelectrode of the capacitor. The material of the conductive plug 214includes conductive materials such as metal or doped polysilicon, etc.The etch stop layer 216 is, for example, disposed on the capacitordielectric layer 212. The material of the etch stop layer 216 is, forexample, silicon nitride or silicon oxynitride.

In the one time programmable memory cell according to the presentinvention, a resistive protection oxide layer or a self-aligned silicideblock layer is served as the capacitor dielectric layer 212. Theconductive plug 214 and the doped region 104 are served as electrodes ofa capacitor. Therefore, a capacitor is fabricated without varying themanufacturing process of common complementary metal oxide-semiconductor.No additional space is required, and the integration of thesemiconductor devices is elevated.

Please refer to the schematic circuit diagram in FIG. 3B, the one timeprogrammable memory cell is formed from a transistor T and a capacitorC. A dielectric layer of the capacitor is damaged by controllingvoltages applied on a gate G, a drain D, a source S and a substrate B ofthe transistor, to program the one time programmable memory cell of thepresent invention. When the dielectric layer of the capacitor has beendamaged (breakdown), the capacitor C in transformed into a resistor R.Therefore, digital data “0” or “1” is recorded by detecting whether thedielectric layer of the capacitor has been damaged (breakdown) or not.Moreover, the dielectric layer cannot be recovered if damaged, so thememory cell can only be programmed one time.

Next, an operating method according to the present invention will beillustrated. FIGS. 4A to 4B are schematic views illustrating programmingoperation of an N type memory cell.

Please refer to FIG. 4A, the memory cell includes a P type substrate (orP type well), a gate, a gate dielectric layer, an N type source regionand an N type drain region, a capacitor dielectric layer and aconductive plug.

When the memory cell is programmed, a voltage V1 is applied on theconductive plug, a voltage V2 is applied on the P type substrate (or Ptype well) and a voltage V3 is applied on the N type drain region, avoltage V4 is applied on the gate. The voltage V4 is such set to open achannel under the gate, the voltage V1 and the voltage V2, V3 are suchset to make capacitor dielectric layer breakdown. For example, thevoltage V1 is about 4 to 6 Volts, the voltage V2 is about 0 Volt, thevoltage V3 is about 0 Volt, the voltage V4 is about 1 to 2 Volts.

Please refer to FIG. 4B, a memory cell includes a P type substrate, adeep N type well DNW, a P type well PW, a gate, an N type source regionand an N type drain region, a capacitor dielectric layer and aconductive plug.

When the memory cell is programmed, the P type substrate and the DNWregion are grounding, a voltage V5 is applied on the conductive plug, avoltage V6 is applied on the gate, a voltage V7 is applied on the N typedrain region, a voltage V8 is applied on the P type well PW. Thevoltages V5, V7 and the voltage V8 are set to make the capacitordielectric layer breakdown. For example, the voltage V5 is about 3.3Volts, the voltage V6 is about 0 Volt, the voltage V7 is about −3.3Volts, and the voltage V8 is about −3.3 Volts.

FIGS. 5A to 5B are schematic views illustrating programming operation ofa P type memory cell.

Please refer to FIG. 5A, a memory cell includes an N type substrate (orN type well), a gate, a gate dielectric layer, a P type source regionand a P type drain region, a capacitor dielectric layer and a conductiveplug.

When the memory cell is programmed, a voltage V9 is applied on theconductive plug, a voltage V10 is applied on the N type substrate (or Ntype well) and a voltage V11 is applied on the P type drain region, avoltage V12 is applied on the gate. The voltages V9, V10 and V11 are setto make the capacitor dielectric layer breakdown. The voltage V12 is setto open a channel under the gate. For example, the voltage V9 is about−3.3 Volts, the voltage V10 is about 3.3 Volts, the voltage V11 is about3.3 Volts, the voltage V12 is about 0 Volt.

Please refer to FIG. 5B, a memory cell includes an N type substrate (orN type well), a gate, a gate dielectric layer, a P type source regionand P type drain region, a capacitor dielectric layer and a conductiveplug.

When the memory cell is programmed, a voltage V13 is applied on theconductive plug, a voltage V14 is applied on the N type substrate (or Ntype well) and a voltage V15 is applied on the gate, a voltage V16 isapplied on the P type drain region. The voltages V13, V14 and V16 aresuch set to make the capacitor dielectric layer breakdown. For example,the voltage V13 is about 0 Volt, the voltage V14 is about 4 to 6 Volts,the voltage V15 is about 3.3 Volts, and the voltage V16 is about 4 to 6Volts.

In the operating method of one time programmable memory cells of thepresent invention, a dielectric layer of the capacitor is damaged bycontrolling voltages applied on a gate, a drain, a source and asubstrate of the transistor, to program the one time programmable ememory cell of the present invention. Moreover, digital information “0”or “1” is recorded by detecting whether the dielectric layer of thecapacitor is damaged or not. The contact area of conductive plug withthe capacitor dielectric layer is relatively small, which can result inincreased current destiny where the conductive plug contacts with thecapacitor dielectric layer when the one time programmable memory cell ofthe present invention is programmed. This can readily make the capacitordielectric layer breakdown and the operating voltages are reduced.

Next, a fabricating method of a one time programmable memory cellsaccording to the present invention will be described.

FIGS. 6A to 6E are cross-sectional views illustrating a manufacturingprocess of a one programmable memory cell according to one preferredembodiment of the present invention.

Please refer to FIG. 6A, at first, a substrate 300 is provided. Thesubstrate 300 includes a silicon substrate, such as an N type siliconsubstrate or a P type silicon substrate. Of course, the substrate 300can also be silicon on insulator substrate.

The substrate 300 is provided with, for example, transistors 302 and304. The transistors 302 and 304 are connected in series, for example.

The transistor 302 is formed with a capacitor dielectric layer 306, agate 308, spacers 310 and source/drain regions 312, 314.

A capacitor dielectric layer 306 is positioned between the gate 308 andthe substrate 300. The material of the capacitor dielectric layerincludes a silicon oxide or high-k material having dielectric constanthigher than 4. The capacitor dielectric layer 306 is formed from one ormore dielectric material layers. The spacers 310 are, for example,disposed on sidewalls of the gate 308. The material of the spacers 310is, for example, silicon oxide or silicon nitride. For example, thesource/drain regions 312, 314 are disposed in the substrate on the sidesof the gate 308. The material of the gate 308 is, for example, dopedpolysilicon.

For example, the transistor 304 is formed from the gate dielectric layer316, the gate 318, the spacers 320 and the source/drain regions 314,322.

A gate dielectric layer 316 is disposed between the gate 318 and thesubstrate 300. The material of the gate dielectric layer 316 includessilicon oxide or high-k material having dielectric constant higher than4. The gate dielectric layer 316 is formed from one or more dielectricmaterial layers. The spacers 320 are, for example, disposed on sidewallsof the gate 318. The material of the spacers 320 is, for example,silicon, oxide or silicon nitride. For example, the source/drain regions314, 322 are disposed in the substrate 300 on the sidewalls of the gate318. The material of the gate 120 is, for example, doped polysilicon.The transistor 302 and the transistor 304 share the source/drain region314.

Forming the transistor 302 and the transistor 304 on the substrate 300is achieved by using common complementary metal oxide-semiconductormanufacturing process. Thus it will not be described in detail.

Please refer to FIG. 6B, a dielectric layer 324 is formed on thesubstrate 300. The dielectric layer 324 is served as a resistiveprotection oxide layer or a self-aligned silicide block layer. Thematerial of the dielectric layer 324 is, for example, silicon oxide orsilicon nitride. Then, a mask layer 326 is formed on the substrate 300.The mask layer 326 covers the dielectric layer 324 of the source/drainregion 314. The material of the mask layer 326 is, for example,photoresist material. For example, the mask layer 326 is formed byfollowing steps. At first, a layer of photoresist material is applied onthe substrate by spinning process. The photolithography process isperformed and the mask layer 326 is formed. Of course, the material ofthe mask layer 326 can also be other materials.

Please refer to FIG. 6C, the mask layer 326 is served as a mask, and aportion of the dielectric layer 324 are removed, only leaving thedielectric layer 324 a on the source/drain region 314. The process ofremoving the dielectric layer 324 includes wet-etching or dry-etching.The wet-etching can use hydrofluoric acid as etchant. Then, the masklayer 326 is removed.

Subsequently, a metal silicide layer 328 is formed on the gate 308, thegate 318, the source/drain region 312 and the source/drain region 322.The material of the metal silicide layer 328 includes metal silicide ofrefractory metal, for example one silicide of nickel, cobalt, titanium,copper, molybdenum, tantalum, tungsten, erbium, zirconium, platinum andalloys thereof. The fabricating method of the metal silicide layer 328is, for example self-aligning metal silicide process. The processincludes following steps: at first a metal layer (not shown) is formedon the substrate 300. The material of the metal layer includesrefractory metal, such as one of nickel, cobalt, titanium, copper,molybdenum, tantalum, tungsten, erbium, zirconium, platinum and alloysthereof. The metal layer is formed by evaporation, sputtering, electricplating, chemical vapor deposition (CVD) or physical vapor deposition.Then, an annealing process is performed, so that silicon of the gates308 and 318, the source/drain regions 312 and 322 reacts with the metallayer, to form a metal silicide layer 328. Then, unreacted metal layeris removed. Removing process of the unreacted metal layer is, forexample, performing a selective wet etch process. The unreacted metallayer is removed by utilizing mixed solution of hydrochloricacid/hydrogen peroxide or mixed solution of sulfuric acid/hydrogenperoxide as etchant, only leaving the metal silicide layer 328 onsurfaces of the gates 308 and 318, the source/drain regions 312 and 322.

Please refer to FIG. 6D, an etch stop layer 330 is formed on thesubstrate 300. The etch stop layer 330 is disposed on and entirelycovers the transistors 302 and 304. The material of the etch stop layer330 is, for example, silicon nitride, which is formed by chemical vapordisposition process. Then, an interlayer insulating layer 332 is formedon the etch stop layer 330. The material of the interlayer insulatinglayer 332 is, for example, phosphorosilicate glass orborophosphorosilicate glass.

Please refer to FIG. 6E, conductive plugs 334, 336 and 338 are formed inthe insulating layers 332. The conductive plug 334 and the conductiveplug 338 are electrically connected to the source/drain region 312 andthe source/drain region 322. The conductive plug 336 extends through theetch stop layer 330 and is connected with a dielectric layer 324 a. Theconductive plug 336, the dielectric layer 324 a and the source/drainregion 314 form a capacitor. The conductive plugs 334, 336, 338 areformed by the steps as following: at first, the insulating layer 332 ispatterned to form plug openings. When a portion of the insulating layer332 is removed to form the plug openings, etching will stop at the etchstop layer 330. Then, the etch stop layer 330 exposed by the plugopenings is removed to expose the metal silicide layer 328 on thesource/drain regions 312 and 322, and the dielectric layer 324 a on thesource/drain region 314. Conductive material is filled in the plugopenings to form the conductive plugs.

In the fabricating method of a one time programmable memory cellaccording to the present invention, a capacitor is directly formed fromthe conductive plug 336, the dielectric layer 324 a and the source/drainregion 314, so the capacitor is fabricated without varying commongeneral complementary metal oxide-semiconductor manufacturing process.The capacitor is directly disposed on the source/drain region 314. Noadditional space is required, and the integration of semiconductordevices is elevated.

As mentioned above, in the semiconductor capacitor, one timeprogrammable memory cell and fabricating method and operating methodthereof according to the present invention, a resistive protection oxidelayer or a self-aligned silicide block layer is served as a capacitordielectric layer, and a conductive plug and a doped region are served aselectrodes of the capacitor. Wherein the doped region is a source/drainregion of a transistor or is fabricated together with a source/drainregion of a transistor in a same manufacturing process. The conductiveplug is fabricated together with plugs connected to a gate, asource/drain region of a transistor in a same manufacturing process.Therefore, the capacitor is directly disposed on the source/drain region314. No additional space is required, and the integration ofsemiconductor devices is elevated.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the following claims.

1. A semiconductor capacitor, comprising: a capacitor dielectric layerwhich is a resistive protection oxide layer or a self-aligned silicideblock layer; and a first electrode and a second electrode disposed atopposing sides of the capacitor dielectric layer, wherein thesemiconductor capacitor is disposed on a substrate; the second electrodeis a doped region disposed in the substrate; the capacitor dielectriclayer is disposed on the doped region, and exposes a portion of thedoped region; and the first electrode is disposed on the capacitordielectric layer.
 2. The semiconductor capacitor according to claim 1,further comprising a metal silicide layer disposed on the doped regionwhich is exposed on the capacitor dielectric layer; and a secondconductive plug electrically connected to the metal silicide layer. 3.The semiconductor capacitor according to claim 1, wherein the firstelectrode is formed from one or more first conductive plugs and theshape of the first conductive plug comprises square, rectangle, round orother shapes.
 4. The semiconductor capacitor according to claim 1,wherein the substrate comprises a silicon substrate or a silicon oninsulator substrate; and the doped region is disposed in a silicon layerof the silicon on insulator substrate.
 5. The semiconductor capacitoraccording to claim 1, wherein the first electrode is a conductive plug.6. The semiconductor capacitor according to claim 1, further comprisingan etch stop layer disposed on the capacitor dielectric layer, whereinthe first electrode extends through the etch stop layer and contactswith the capacitor dielectric layer.
 7. A semiconductor capacitor,comprising: a capacitor dielectric layer which is a resistive protectionoxide layer or a self-aligned silicide block layer; and a firstelectrode and a second electrode disposed at opposing sides of thecapacitor dielectric layer, wherein the semiconductor capacitor isdisposed on an isolation structure of a substrate; the second electrodeis a doped polysilicon layer disposed on the substrate; the capacitordielectric layer is disposed on the doped polysilicon layer and exposesa portion of the doped polysilicon layer; and the first electrode isdisposed on the capacitor dielectric layer.
 8. The semiconductorcapacitor according to the claim 7, further comprising a metal silicidelayer disposed on the doped polysilicon layer which is exposed on thecapacitor dielectric layer; and a second conductive plug electricallyconnected to the metal silicide layer.
 9. The semiconductor capacitoraccording to claim 7, wherein the first electrode is a conductive plug.10. The semiconductor capacitor according to claim 7, further comprisingan etch stop layer disposed on the capacitor dielectric layer, whereinthe first electrode extends through the etch stop layer and contactswith the capacitor dielectric layer.
 11. A semiconductor capacitor,comprising: a capacitor dielectric layer which is a resistive protectionoxide layer or a self-aligned silicide block layer; and a firstelectrode and a second electrode disposed at opposing sides of thecapacitor dielectric layer, wherein the semiconductor capacitor isdisposed on an insulating substrate; the second electrode is a dopedsemiconductor layer disposed on the insulating substrate; the capacitordielectric layer is disposed on the doped semiconductor layer, andexposes a portion of the doped semiconductor layer; and the firstelectrode is disposed on the capacitor dielectric layer.
 12. Thesemiconductor capacitor according to the claim 11, wherein theinsulating substrate is a glass substrate.
 13. The semiconductorcapacitor according to claim 11, wherein the first electrode is aconductive plug.
 14. The semiconductor capacitor according to claim 11,further comprising an etch stop layer disposed on the capacitordielectric layer, wherein the first electrode extends through the etchstop layer and contacts with the capacitor dielectric layer.